Ah, now I am glad I stuck with DSSSL :)
It's just a rpi plugged into a standalone numeric keypad, acting as a jukebox. Playlists are numbered.
By the time my kids were about three, they could enter the numbers on their own, and by four they had memorized the playlists so well they didn't look at the printed catalog any more.
So what I was trying to say is: Why can't shipping containers be more "automatically" routed over rail? Perhaps fully automatic rail car couplers would be more helpful in general than yet another gadgetbahn?